Jobsite Safety

Letter to the editor: Nail Gun Safety

Late last year we published a story about Eugene Rakow, a Minnesota carpenter who accidentally shot himself through the heart with a framing gun—and miraculously, survived. In it I commented on the mistakes Rakow made, using the gun in an unsafe orientation and after the accident calling his wife instead of 911.

Hester Lipscomb, a professor of occupational and environmental medicine at the Duke University Medical Center, sent a letter (see below) that said I was blaming the victim when I should have been focusing on a simple technology that could have prevented the accident—a sequential-trip trigger. Lipscomb is qualified to comment, having been involved in a number of studies related to nail gun safety, including one where groups of carpenters were timed building identical sheds with sequential- and contract-trip guns. In that study, using a sequential-trip trigger increased active nailing time by 10% but the overall time of construction by only 0.77%. In the opinion of the study’s authors, adding 0.77% of construction time is a negligible price to pay for a reduction in nail gun injuries.

What’s your take on Rakow’s technique (see demonstration at 28-second mark in the video), Lipscomb’s response to my comments, and the study comparing the speed of nailing with sequential- and contact-trip guns? Feel free to respond in the comment section at the bottom of this page—and remember, this is a polite debate. I may not agree with everything Lipscomb and other safety experts want us to do, but I have to acknowledge that they’ve given the issues serious study.

December 16, 2013

Letter to Dave Frane re Tools of the Trade

There is more to safety than just being careful….

In late October, the news of a Minnesota carpenter barely escaping death from a nail gun injury to the heart drew national attention. As you reported, the nail penetrated his sternum and pierced his heart within millimeters of the coronary artery. According to the doctors, had the artery been severed [he] almost certainly would have died.

You went on to comment on the actions of the carpenter including using the gun the way he did and calling his wife instead of 911.

It is sad to see these comments that essentially blame the injured carpenter for not being more careful or using better judgment. Unfortunately, many users of nail guns, even frequent users, fail to recognize the dangers associated with the use of the tool. Even fewer know that there is an engineering solution that reduces their injury risk substantially.

For the last dozen or so years we (a university professor and two union carpenters who became research partners) have studied injuries from pneumatic nail guns in residential building. Let us share with you some of the things we have learned.

There are nearly 40,000 nail gun injuries treated in emergency departments in the U.S. each year. The decreasing costs and easy availability of the tools has extended what was once largely an occupational risk to the general public who use the tools for personal projects.

Nail guns are the most common cause of tool-related hospitalization among workers in the construction industry. This is of note given that their use is limited to wood frame construction.

Over 10% of injuries are to bystanders; these typically involve inadvertent shooting of a co-worker.

As in the Minnesota carpenter’s case, injuries are largely associated with framing nailers with contact trip triggers. Contact triggers allow the gun to discharge a nail anytime the nose piece and the trigger are both depressed. This means users can hold the trigger down and rapidly bump fire the gun; it also means you can shoot a co-worker or yourself if you bump the nose piece when the trigger is depressed. Contact triggers also allow inadvertent firing if the nose piece hits something following the recoil that goes along with the discharge of a nail while the users finger is still on the trigger. We have seen many injuries sustained this way – and this seems to be the manner in which this carpenter was injured. The tool recoiled and swung in towards him – which is not unheard of either. When the nose contacted his chest his finger was still on the trigger and the gun discharged. Although portrayed as a rare event in the press, others have sustained similar types of injuries from nail guns.

Users of tools with contact triggers are twice as likely to be injured as users of tools with sequential triggers. Tools with sequential triggers require the nose be depressed before the trigger is pulled in order to prevent inadvertent discharge of nails and injuries such as this one.

Most injuries involve puncture wounds to the hand or fingers but injuries to other body parts and internal organs, as this carpenter experienced. Nail gun injuries can be among the most expensive work-related injuries in residential carpentry and they can cause death.

Our findings from field studies over the last decade are entirely consistent with laboratory studies that report the following:

Nailers with touch tip triggers (contact) are susceptible to double firing, especially when trying to accurately place the nailer against the work piece during toe-nailing. In awkward positions the user is less likely to hold the nailer firmly enough to counter the nailer’s recoil. The recoil and firing of the second nail occurs well before the trigger can be released.

The sequential trigger was expressly designed to prevent this type of injury. And, if you are wondering if the injuries can really be prevented, we have good evidence that they can. We have seen injuries decrease as workers increased their use of tools with sequential actuation. Users of the tools need training in safe tool use even though these tools are very easy to operate. But even among trained users, the risk of injury is twice as high when using tools with contact triggers.

There are lots of very difficult safety issues in construction...this should not be one of them. Help spread the word that sequential is safer!